Hello all,

Been recently dealing with a slow tapping noise on cold start (doesn't seem to happen when starting in hot weather or having driven prior). Sometimes presents as a squeak instead of a tap. Seems to be coming from the driver side cylinders. Slows down a bit when in gear and goes away after a minute or two or once I start driving. Noise seemingly started to happen a few hundred miles after I changed spark plugs and drive belt. Rechecked spark plug gaps and tried swapping plugs and coil packs on each side, noise still remains. Oil level is good. No CEL or codes and haven't noticed any performance issues. Don't think it is an exhaust manifold leak after checking with smoke machine and stethoscope. Any thoughts?

Video: 1GR Tapping Noise

Sounds like either a cracked exhaust manifold or bad exhaust manifold gasket! When it heats up, the metal expands and stops the tick noise.

Same here. Positive its an exhaust manifold leak. AT about $1500 to fix its just something I'll learn to live with.....

Until it eventually burns up a valve and then you're looking at double that minimum.

I've recently been dealing with a P0430/P0174 codes. I checked with a smoke machine for any vacuum/exhaust leaks and only found one where the manifold joins the 2nd cat. Replacing the gasket sealed it up.

Does this mean you think there's more than just an exhaust leak?

What he means is with an exhaust leak if it's severe enough it can can damage a valve if cold air gets in contact with a hot valve.

But I've never heard of an exhaust leak causing a burnt valve, only warping a valve, but the result is the same, you lose the power from that cylinder.